Optical networking transport systems typically use an optical line terminal (OLT) that provides a high bandwidth passive optical network (PON). The PON is split, using an optical splitter, to multiple optical network termination (ONT) points. The use of, for example, thirty two (32) ONTs allows multiple users to share the same high bandwidth OLT. However, the number of ONTs may be expanded to up to one hundred and twenty eight (128) in some implementations
In use, the OLT and ONTs communicate with the PON using a time division multiplexing (TDM) scheme to allow for each ONT to communicate in an orderly fashion. The use of the optical splitter allows each ONT to share the same OLT and share the costs for the PON system. The TDM scheme is a method for transmitting multiple channels over the single PON line. Each ONT is assigned a periodic timeslot to receive and transmit to the OLT. Thus, there are two slots available to an ONT that include a downstream slot and an upstream slot. Where a packet is too large for a single timeslot, the packet is subdivided and periodically transmitted over a number of the assigned timeslots.
Existing systems have drawbacks wherein ONTs may malfunction and interfere with the timeslots of ONTs on upstream communication. In these cases, the malfunctioning ONT is considered a rogue ONT. The rogue ONT may interfere with upstream communications in a number of ways. For example, a rogue ONT may have timing or synchronization problems wherein an upstream communication is transmitted in the assigned time of another ONT in the TDM scheme. Further, an ONT may overload the OLT with too much optical power. The overload may occur in its own TDM timeslot or in adjacent timeslots. The result of the overload, may include, for example, either an inability for the OLT to receive the desired signal or an interference with other ONTs. This is especially an issue where the rogue ONT is optically close to the OLT, while the ONT with the desired signal is at the edge of the supported distance or optical budget. Additionally, the rogue ONT may confuse the PON to such an extent that a majority of the processing power of the PON is consumed and regular communication with the ONTs is interrupted.
Accordingly, it is highly desirable to be able to detect and correct the operation of a rogue ONT. Further, it is desirable to determine the nature of the faults for a rogue ONT and either correct the problem or disable the offending rogue ONT. Additionally, it is highly desirable to perform these detection and correction functions remotely.